Met 4 college girls holding hands and signing loud songs to show themselves how unafraid they were. They did not see me (it being a new moon and a really dark forest trail), until one of them brushed past me with her sleeve.

Ow.

After the initial screaming session, the hapless victims fled in various directions, breaking formation. When the initial moment of confusion passed, they regrouped in an orderly fashion and proceeded down the trail at an unseemly pace, screaming all the while. I did my best evil cackle, but it came off wrong, and resulted in a sort of maniacal cough.